| Protocol | Protocol Number |
| EIGRP | 88 |
| OSPF | 89 |
In this type of communication, first device send data and second device receive it. Second device never send any information to first device. Broadcast systems like FM radio work in this way.
In this type of communication, when first device send data, second device receives it and when second devices send data, first device receives it. But both devices can’t send or receive data at the same time. This type of communication is using in "walkie-talkie".
In this type of communication, first and second device can send and receive data simultaneously. Phones and mobile phones are using this type of communication.
Note: In Ethernet communication we can set both end half or full duplex depending up on the requirements. That is Ethernet can work on both mode.
Before begin configuration we need to see the current status of switch. This can be don using verity of ‘show’ commands. Some of them are given below
Now, lets set the interface attributes
The syntax is as follows:
interface type mod/port
speed {10 | 100 | 1000 | auto} ;This command tells transmission speed. It can be set depending on Speed of Interface. Normally Switch detects the speed correctly. Default configuration is “auto” ie. automatically detect the speed
duplex {half | full | auto} ;set the duplex of interface. Default is auto. But it is better to hardcode by command on both side. If you set duplex to auto then make it on both side. Also, if you set duplex make sure that it is typed on both side, otherwise mismatch will happen. If you don’t know about duplex, please check here
mdix auto ;This is the default setting. . This permit switch to automatically discover if a crossover connection is needed. we can change the setting by “no mdix auto” command
media-type {sfp | rj45} ;detects automatically. sfp used for fiber optic ports
Sample configuration is given below:
SW1(config)#interface fa0/1
SW1(config-if)#speed 100
SW1(config-if)#duplex full
SW1(config-if)#no shut (to enable the interface)
Ok. That’s enough. But the problem is, we have to type it on all interface. Hmm… It has an easy way – use the ‘range’ command
SW1(config)#int range fa 0/1 - 4 , fa0/15 ;comma is surrounded by space. This will select the specified range of interfaces i.e. from fa0/1 to fa0/4 and fa0/15 at the same time. Now we can set any attributes to that interface.
SW1(config-if-range)#shut
SW(config-if)#power inline {auto|never} :to automatically discover power need by port or disable power
SW(config-if)#power inline {consumption mw | static max mw} : to give power specifically
Inline Power and PoE are used to provide power to IP phones, wireless access points etc. by the catalyst switch trough the same data cable.
In the reality, as you may know, out of 8 channels in the UTP cable, only 4 is used for data transmission. So these methods use the rest to provide power to the devices. 
Cisco Provides 3 methods to deliver current through the Ethernet cable:
| Property | Inline Power | 802.3af | 802.3at PoE+ |
| Standard | Cisco Proprietary | IEEE standard | IEEE standard |
| Maximum power delivery | 7W/port | 15.4W/port | 34.20 W |
| Cable speed | 10/100 only | Compatible with gigabit Ethernet | Compatible with gigabit Ethernet |
| Compatibility | Incompatible with all non-Cisco devices that accept power over Ethernet | Not compatible with Cisco inline power – the power negotiation process is completely different | Backward compatible with 802.3af |
The devices connecting to the port are divided into different classes depending up on the power consumption:
| Class | Max Power | |
| 0 | 15.4 W | Default |
| 1 | 4.0 W | |
| 2 | 7.0 W | |
| 3 | 15.4 W | |
| 4 | Undefined | Future Use |
Switch#show power inline ;to see the current status of ports
Switch(config-if)#power inline {auto|never|delay}
Switch(config-if)#power inline {consumption mw | static max mw} ;to give power specifically
Note: We don’t need to type any command. Cisco switch detect all cisco devices and power needed by the devices automatically using CDP.
VTP stands for VLAN Trunking Protocol. Unlike the name implies, VTP is used for replication of VLAN information. That means, we just need to create VLANs or edit VLAN information only on one switch. Then VTP will transfer that information through the trunk link to all other switches which make the administration centralized.
VTP works based on the revision number. By default, VTP revision number is 0 on all switches. If we change any VLAN information on a switch, like… adding VLAN, deleting VLAN, renaming VLAN, etc.. the revision number increases. When other switches get the VTP update, it check the VTP revision number contained in the update with its on VTP revision number. If the local revision number is lower than the one it received, it replace the whole VLAN database with the currently received database.
VTP has three modes – Server, Client and Transparent. Depending upon VTP mode in which the switch operates, it gets the features as follows:
By default cisco switches comes with VTP server mode. Because of there is no VTP Domain name applied to new switches, they act as server for themselves. Also, switches doesn’t participate in VTP until they hear VTP advertisement from another switch.
To see the current VTP status, use the following command
SW1#show vtp status
Now lets make VTP run on every switch as in the figure.
SW1# vtp domain TestDomain
SW2# vtp domain TestDomain
SW3# vtp domain TestDomain
Note: If there is no domain name exist in all switches, then if we configure domain name on SW1, all switches get it automatically.
SW1# vtp mode server
SW2# vtp mdoe transparent
SW3# vtp mode client
eg: SW1# vtp password P1ssw0rd
Note: if we want to set the password, set it on all switches
Default VTP version is 1. if we want to change it to version 2, then do the following command on all switches
eg: SW1# vtp version 2
If we accidently connect a switch with higher revision number and same domain name to the network, all the switches will replace their database to it’s database. Then network connection may not available to users.
Solution:
Before attaching the switch to the network, reset its revision number to zero. Do one of the following to reset revision number to 0
Private VLAN is the technique of dividing single VLAN into different sub VLANs. This is generally used in the ADSL networks. Also, we can use it to simplify the IP address assignment because all ports are in the same subnet, although they are logically separated in the data link layer.
Private VLAN contains two components
Secondary VLANs can be one of these:
Now lets, Create these VLANs as in the figure
Sw1(config)# vlan 100
Sw1(config-vlan)#private-vlan community
Sw1(config)# vlan 200
Sw1(config-vlan)#private-vlan community
Sw1(config)# vlan 300
Sw1(config-vlan)#private-vlan isolated
Sw1(config)# vlan 500
Sw1(config-vlan)#private-vlan primary
Sw1(config-vlan)#private-vlan association 100,200,300
To proceed to next step, we must understand about different types of ports
There are mainly two types of port in Private VLAN - Promiscuous port and Host port. Host port is further divides into two types - Isolated port and Community port.
Now, lets assign these different types of port to different VLANs we created. Remember, every ports except Promiscuous port are host port. So the VLAN which we assign these ports determines whether it is isolated port or community port.
SW1(config)#int range e0/1 - 2
SW1(config-if-range)#switchport
SW1(config-if-range)#switchport mode private-vlan host
SW1(config-if-range)#switchport private-vlan host-association 500 300
SW1(config)#int range e1/0 - 1
SW1(config-if-range)#switchport
SW1(config-if-range)#switchport private-vlan host-association 500 100
SW1(config)#int range e1/2 - 3
SW1(config-if-range)#switchport
SW1(config-if-range)#switchport private-vlan host-association 500 200
SW1(config)#int e0/0
SW1(config-if)#switchport
SW1(config-if)#switchport mode private-vlan promiscuous
SW1(config-if)#switchport private-vlan mapping 500 100,200,300
| Port | TCP | UDP | Description |
| 20 | x | FTP-Data | |
| 21 | x | FTP (login access) | |
| 22 | x | x | SSH |
| 23 | x | Telent | |
| 25 | x | SMTP (Mail, MTA) | |
| 49 | x | TACACS+ | |
| 53 | x | x | DNS |
| 69 | x | TFTP | |
| 80 | x | x | HTTP (Web) |
| 110 | x | x | POP3 (email); generally uses TCP) |
| 119 | x | NNTP (Usenet News) | |
| 123 | x | NTP | |
| 139 | x | x | NetBIOS (Microsoft) |
| 143 | x | x | IMAP |
| 161 | x | x | SNMP (Network Monitor) |
| 179 | x | BGP | |
| 443 | x | x | HTTPS |
| 465 | x | SMTPS (Secure Mail over SSL) | |
| 993 | x | x | IMAP (Secure IMAP over SSL) |
| 995 | x | x | POP3S (Secure POP3 over SSL) |
| 1645,1812 | x | RADIUS Authentication | |
| 1646,1813 | x | RADIUS Accounting |
ASA(config)#policy-map global_policy
ASA(config-pmap)#class inspection_default
ASA(config-pmap-c)#inspect icmp
Our company may have two connection to the internet through 2 ISPs. If we want to use one connection as primary and other as backup, we can use IP SLA to monitor the link. It detects the link failure even if the connection between modem and ISP fails. So it helps to switch over to the backup path automatically as soon as the primary path is down.
Step1 : Configuring SLA process
R1(config)#ip sla 1
R1(config-ip-sla)#icmp-echo 8.8.8.8
R1(config-ip-sla-echo)#frequency 5 (Means, every 5 second send icmp-echo packet to the ip 8.8.8.8. This can by any reliable IP on internet)
R1(config-ip-sla-echo)#exit
Step2: Scheduling SLA process
R1(config)#ip sla schedule 1 start-time now life forever (Means, start the sla process now and don’t end)
Note: we can check the process using the following command
R1#show ip sla statistics
Step3: Create a track object to track the change. It is used to inform the router about the current condition
R1(config)#track 10 rtr 1 reachability (this will inform the router if any reachability problem occurs. rtr is the old name of IP SLA)
R1(config-track)#exit
Step4: Create two static route two both ISPs with some tweaks
R1(config)#ip route 0.0.0.0 0.0.0.0 fastEthernet 0/0 track 10
R1(config)#ip route 0.0.0.0 0.0.0.0 fastEthernet 0/1 2
Now router will select ISP1 as primary path because of administrative distance is lower. If the link to ISP1 is down, then router automatically switch the connection to ISP2
ASA1(config)#route inside 172.30.10.0 255.255.255.0 172.30.30.2 1
ASA1(config)#route inside 172.30.20.0 255.255.255.0 172.30.30.2 1
ASA1(config)#route outside 0.0.0.0 0.0.0.0 192.168.1.2Note: we can use the command “route outside 0 0 192.168.1.2” for default route, both are same.
R1(config)#username binoy privilege 15 secret ciscoNow download SDM from www.cisco.com/go/sdm and install it in the computer (requires java runtime environment) and launch the SDM by giving IP address in SDM launcher
R1(config)#ip http server
R1(config)#ip http secure-server (allows encrypted access)
R1(config)#ip http authentication local
| Connected interface | 0 |
| Static route | 1 |
| Enhanced Interior Gateway Routing Protocol (EIGRP) summary route | 5 |
| External Border Gateway Protocol (BGP) | 20 |
| Internal EIGRP | 90 |
| IGRP | 100 |
| OSPF | 110 |
| Intermediate System-to-Intermediate System (IS-IS) | 115 |
| Routing Information Protocol (RIP) | 120 |
| Exterior Gateway Protocol (EGP) | 140 |
| On Demand Routing (ODR) | 160 |
| External EIGRP | 170 |
| Internal BGP | 200 |
| unknown | 255 |
rommon 1 > IP_ADDRESS=172.30.10.20 (gives IP address to current device)
rommon 2 > IP_SUBNET_MASK=255.255.255.0
rommon 3 > DEFAULT_GATEWAY=172.30.10.1
rommon 4 > TFTP_SERVER=172.30.10.100
rommon 5 > TFTP_FILE=c3640-jk9o3s-mz.123-14.T7.bin
rommon 6 > tftpdnld (this command will start the download of IOS from TFTP server)
